Machine for impregnating and coating web material



P. VALLE May 30, 1967 MACHINE FOR IMPREGNATING AND COATING WEB MATERIAL Filed Dec. 4, 1964 lanv n flTTO/UVEY IN V ENTOR.

Power Jource F0 wersource United States Patent 3,322,099 MACHINE FOR IMPREGNATING AND COATING WEB MATERIAL Pierre Valle, Lyon, Rhone, France, assignor to Societe Industrielle des Silicones, Paris, France Filed Dec. 4, 1964, Ser. No. 415,991 Claims priority, application France, Dec. 6, 1963, 956,335 2 Claims. (Cl. 118-642) The present invention relates to machines for continuously impregnating and coating web material such as cloth, paper or plastic tape.

More specifically, it relates to a machine capable of either full bath impregnation of web material with a solution or dispersion of a resin, a plastic material, an elastomer, or more particularly, a heat hardenable or polymen'zable composition, or any other substance such as a coloring material or an antiseptic, deodorant, pesticide, etc., or the coating of a web of material such as cloth, paper or plastic tape with the said solution or dispersion, then holding the treated web at a temperature sufiicient to achieve drying and/or hardening or polymerization of the solution or dispersion retained by the web.

Machines for realizing similar ends are already known, but because of their complicated construction, such machines display the disadvantage of contacting the freshly coated side of a web with the surface of at least one guide roller or driving drum before introducing the web into an oven for drying and polymerization, a contact which is detrimental to the finish of the coated side of the web. Other disadvantages are found in the web handling and impregnation apparatus of prior art machines.

Accordingly, it is an object of the present invention to provide an improved web impregnating and coating machine.

The applicant has found, according to the present invention, that the problem of coating contacts with rollers and drums can be remedied by reversing the direction of rotation of the machines entry drum so that this drum, supporting the tape to be coated at the time it is being coated, turns in the opposite direction from that which is given it when the machine is effecting impregnation. Further, improved guiding and impregnating of systems are provided. Other objects and advantages of the invention will appear from the description which follows when read in conjunction with the attached drawing in which:

FIG. 1 is a diagrammatic view in elevation and partial cross-section of an embodiment of the invention, and

FIG. 2 is an end elevational view of the web stretching roller of the embodiment of FIG. 1. As shown in the drawings, the machine comprises two main sections: the impregnation or coating apparatus, and the oven for drying and for polymerization. Said apparatus permits the assembly of the pieces necessary to effect either impregnation or coating of a cloth, paper, etc., tape but traveling a different path depending on whether it is to be impregnated or coated. Some constituent parts of the machine function, both for the impregnation as for the coating while others function only in one of these processes.

When the machine is used for impregnating a web composed, for example, of a cloth 11, the cloth is initially supplied from a web supply means 12, such as reel, and may be started through the machine by means such as a chain running the length of the course, including the oven, and which is drawn by an apparatus not illustrated, situated at the exit of the machine. The web passes, via guiding means, such as rollers 13 and 14 onto an entry drum 15 of larger diameter, turning clockwise, then via further guide means 16 onto at least one web width stretching roller 17 permitting it to stretch in width and ice thus to avoid wrinkles. The web width stretching roller 17 is of variable diameter as is shown in greater detail in FIG. 2. Finally, guided by roller 18, the cloth passes into contact with a group of 3 treatment rollers 19, 20 and 21, which turn partly immersed in an impregnation bath 22, andthus, transfer the liquid of the bath onto the cloth which is then pre-impregnated. The preimpregnation is most eflicacious when the outside rollers 19 and 20 turn in the direction of advancement of the web and the central roller 21 turns in the opposite direction, so that the impregnating fluid penetrates the pores better. Actually, the impregnation is completed when the web passes around a further treatment roller 23, which is totally immersed in the impregnation bath.

In leaving the bath 22 the web is air dried by passing it through an apparatus formed of numerous bars 24, and/or between two squeeze rollers turning in opposite directions and having between them a variable space regulated by means of a micrometric screw or the like (not shown). The impregnated and suspended web then passes through a vertical oven 26, wherein it is dried while, if desired, the hardening or the polymerization of the impregnating substance is effected. Upon leaving the oven the impregnated and dry web passes over a pair of guide rollers 27 and 28, which make it descend at the exterior of the oven where, in passing a speed regulating roller 29, it passes onto the exit drum 30, which turns slightly faster than the entry drum 15 by virtue of which the cloth is held taut lengthwise, before being wound onto a roll 31 for storage. The excess speed of the exit drum 30 implemented by the speed varier 29 may be absorbed by a known apparatus such as a slip clutch, not illustrated. The web supply means 12, and/or the entrance drum 15 may be either driven at a lower speed than the exit drum, or may be provided with friction braking in order to provide web tension.

When the machine is used for coating instead of im pregnation, the direction of rotation of the entrance cylinder 15 is reversed and it turns counter clockwise. The roll of cloth 32 is then placed in a position permitting the cloth to pass by means of guiding means such as rollers 33 and 34, around the entry drum 15. Coating composition is spread onto the cloth passing over the entry cylinder 15 by means such as a nozzle 35, the depth of the coating being regulated by means such as a scraper 36, which may act either adjacent the surface of the drum or along a reach of the Web. As shown by the broken lines, the entry drum 15 has been shifted to contact the nozzle and scraper. Obviously, the drum may remain fixed and the nozzle and scraper may be shifted into an operational position. The freshly coated cloth then passes directly over a guiding roller 37 so that the coated side does not come in contact with the surface of the roller, but remains on the outside and while crossing the oven, that side is constantly turned toward the central longitudinal axis of the same. When leaving the top of the oven, the coated cloth, being dry and the coating material hardened or polymerized, can be taken up again without danger to the coating by rollers 27, 28, 29, 30 and 31, that is to say, by the same final circuit used in the impregnation.

The vertical oven used for drying and/or hardening or polymerization in the case of impregnation as well as in coating, is preferably heated electrically by means of resistances 38, 39 and 40, located to obtain a uniform temperature and supplied by suitable regulatable power sources. Heating may be controlled and automatically regulated with great precision by means of three regulating installations, independent from each other, which permit dividing the oven into three heat zones having different predetermined temperatures. A system of sliding web material impermeable or wrinkle resistant or odorless or fragrant or to confer resistance to destructive agents such as mites, or for coloring or decorating.

It is, more particularly, applicable for the fabrication of pre-impregnated layers for the preparation of laminated fabrics, or in the fabrication of web material coated with an elastomer dispersion.

The method of manufacturing the machine and of its function according to the present invention, as Well as the applications cited above, are not intended in a limit-- ing sense, and it is possible to modify the details of the machine, or to apply treatments other than those which are described above without departing from the scope of the invention.

Thus, for example, the tension of the tissue across the machine can be realized by putting it on a mobile support such as an endless band; the web leaving the oven can be made to descend through the interior of the latter and not the exterior; one can equip the machine with regulatable means for guiding the tissue, to obtain the desired longitudinal and transverse tension, and if desired, of its support; the oven can be placed horizontally instead of vertically; it can be heated by other known means than those of electrical resistance, for example by infrared rays, by gas heat, water vapor, or other means. Other modifications, and variations will become obvious to those skilled in the art. Accordingly, within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

That which is claimed is:

1. A machine for coating or impregnating a web, comprising:

a pair of spaced web supply means,

a web entry drum spaced from said Web supply means, positioned between said web supply means, and being mounted for rotation in both clockwise and counterclockwise directions;

guiding means interposed between said web supply means and said web entry drum for feeding the web from one of said pair of web supply means onto said drum in a clockwise direction and for feeding the web from the other of said web supply means onto said drum in a counter-clockwise direction,

a treatment bath for impregnating said web,

guide means for feeding said web'from said web entry drum through said treatment bath for impregnation,

a curing station,

guide means for feeding said web from said treatment bath through said curing station,

Web coating means,

means for selectively placing said web coating means in an operative position with respect to the outer surface of said web as it passes over said web entry drum, whereby one surface of said web is coated,

means for feeding said coated Web from said web entry drum into and through said curing station without any physical contact to said coated surface of said web, and

web storage means for receiving said web from said curing oven. 2. A machine for coating or impregnating a web as defined in claim 1 wherein said curing station comprises electrical heating means including a plurality of selectively adjustable zones.

References Cited UNITED STATES PATENTS CHARLES A. WILLMUTH, Primary Examiner.

J. P. McINTOSH, Assistant Examiner. 

1. A MACHINE FOR COATING OR IMPREGNATING A WEB, COMPRISING: A PAIR OF SPACED WEB SUPPLY MEANS, A WEB ENTRY DRUM SPACED FROM SAID WEB SUPPLY MEANS, POSITIONED BETWEEN SAID WEB SUPPLY MEANS, AND BEING MOUNTED FOR ROTATION IN BOTH CLOCKWISE AND COUNTERCLOCKWISE DIRECTIONS; GUIDING MEANS INTERPOSED BETWEEN SAID WEB SUPPLY MEANS AND SAID WEB ENTRY DRUM FOR FEEDING THE WEB FROM ONE OF SAID PAIR OF WEB SUPPLY MEANS ONTO SAID DRUM IN A CLOCKWISE DIRECTION AND FOR FEEDING THE WEB FROM THE OTHER OF SAID WEB SUPPLY MEANS ONTO SAID DRUM IN A COUNTER-CLOCKWISE DIRECTION, A TREATMENT BATH FOR IMPREGNATING WEB, GUIDE MEANS FOR FEEDING SAID WEB FROM SAID WEB ENTRY DRUM THROUGH SAID TREATMENT BATH FOR IMPREGNATION, A CURING STATION, GUIDE MEANS FOR FEEDING SAID WEB FROM SAID TREATMENT BATH THROUGH SAID CURING STATION, WEB COATING MEANS, MEANS FOR SELECTIVELY PLACING SAID WEB COATING MEANS IN AN OPERATIVE POSITION WITH RESPECT TO THE OUTER SURFACE OF SAID WEB AS IT PASSES OVER SAID WEB IS COATED, DRUM, WHEREBY ONE SURFACE OF SAID WEB IS COATED, MEANS FOR FEEDING SAID COATED WEB FROM SAID WEB ENTRY DRUM INTO AND THROUGH SAID CURING STATION WITHOUT ANY PHYSICAL CONTACT TO SAID COATED SURFACE OF SAID WEB, AND WEB STORAGE MEANS FOR RECEIVING SAID WEB FROM SAID CURING OVEN. 